Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Physiology Exam 1(Lauren) > Control Of Extracellular Fluid > Flashcards

Control Of Extracellular Fluid Flashcards

1
Q

Na+ regulation responds primarily to changes in _____________

A

Blood volume

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Water regulation responds to changes in _________ and _________ of ECF

A

Osmolarity

Volume

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Na+ retention entails loss of ____

A

K+

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What are the 2 ways that aldosterone can be activated/

A
  1. Angiotensin II
  2. K+ plasma concentrations increase (remember that aldosterone will stimulate Na+ reabsorption, which will entail K+ loss)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Aldosterone binds to the intracellular _______________ receptor in __________ cells

A

Mineralocorticoid

Principal

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What does spironolactone do?

A

Binds to the mineralocorticoid receptor and prevents aldosterone from having an effect

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What are the effects of aldosterone?

A

It stimulates transcription, resulting in up-regulation of:
Apical ENaCs

apical K+ channels

Na+,K+ ATPase

Mitochondrial metabolism

H+ ATPase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What are the effects of angiotensin II?

A

Vasoconstrictor

Activates aldosterone

Stimulates Na+/H+ exchange in proximal tubule (NHE antiport)

Makes you thirsty

Overall- salt retention and elevation of BP

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What is a dipsogen?

A

Stimulates thirst

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What hormone regulates the levels of Angiotensin II?

A

Renin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What cells release renin?

A

Granular cells (aka juxtaglomerular cells)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What 3 mechanisms can stimulate renin release?

A
  1. Intrarenal barorecpetors in the granular cells of JGA respond to stretch in afferent arterioles (Low BP=HiGh renin release)
  2. Macula Densa senses flow to the distal tubule (NaCl levels) and will cause renin release if GFR is too low
  3. Renal Sympathetic Nerves near granular cells will increase renin release via stimulation of β receptors
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

How does renin release lead to angiotensin II floating around?

A

Renin cleaves angiotensinogen floating around in the blood to make angiotensin I, and then the whole ACE to angiotensin II thing

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Where does atrial natriuretic peptide come from?

A

Atria of the heart

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

When do the atria release ANP?

A

When BP is high

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What effect does ANP have on the kidney?

A
  1. Increases GFR

2. Decreases NaCl reabsorption by the CD

17
Q

How does ANP increase GFR (and thus, the filtered load of NaCl)?

A

Dilates the afferent arteriole and constricts the efferent arteriole

18
Q

How does ANP decrease NaCl reabsorption by the Collecting Duct?

A
  1. Directly inhibits secretion of renin and aldosterone

2. Directly inhibits Na+ uptake by medullary CD

19
Q

What is the most important hormone regulating water balance?

A

ADH

20
Q

Where does ADH come from?

A

Pituitary gland

21
Q

What cauwses the release of ADH from the pituitary ?

A

Increased plasma osmolality

Plasma volume decreases

22
Q

Does ADH have an effect on NaCl excretion?

A

Very little

23
Q

Which is the primary controller of ADH release: plasma osmolality or plasma volume

A

Plasma osmolality

24
Q

What is the average osmolarity of the body?

A

290 mOsm/L

25
Q

If your plasma volume changes just a little, will ADH get released?

A

No you need a pretty significant loss of plasma volume (about 10%)

26
Q

Will a teeny tiny change in plasma osmolarity cause release of ADH?

A

Yes

27
Q

If you drink a ton of water will you release ADH?

A

No, and the collecting duct permeability to H2O will be diminished, so you will lose H2O in your pee

28
Q

How could a decrease in plasma volume lead to an indirect release of ADH?

A

SNS detects lower plasma volume-> SNS activity-> renin secretion -> aldosterone -> renal sodium conservation -> increased plasma osmolarity -> ADH release

29
Q

If you drink a ton of water, your urine volume will increase. Will you also be peeing out a lot of solutes?

A

No, the amount of solute excretion will remain relatively constant

30
Q

What is clearance?

A

The ml/min of blood plasma cleared of a given substance

31
Q

What is Osmolar Clearance?

A

The ml/min of blood plasma cleared of osmotically active particles

32
Q

How do you calculate osmolar clearance?

A

(Uosm)(V)
_____________
Posm

Uosm = osmolarity of Urine

Posm- osmolarity of plasma

33
Q

What is a normal Osmolar clearance?

A

1-2 ml/min

34
Q

What does it mean if your Cosm (osmolar clearance) decreases?

A

You are not getting rid of enough solutes

-POSITIVE osmolar balance = gaining osmoles and water and progressing towards edema

35
Q

What can cause a reduced Cosm?

A

Decreased GFR

Increased Aldosterone (inapp. Reabsorption of sodium)

Kidney disease that decreases kidney’s ability to eliminate solute

36
Q

If someone develops edema, do you think their Cosm went up or down?

A

Down.

Reduced Cosm= not getting rid of enough solutes

37
Q

What effect will diuretics have on Cosm?

A

Increased. Will cause you to “dump” osmolytes and ECF will decrease

38
Q

What kinds of things can cause an increased Cosm?

A

Diuretics

Reduced aldosterone

Kidney disease that prevent normal reabsorption

Physiology Exam 1(Lauren) (12 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions